Groin



Oct. 25, 1966 w. B. WOSENITZ GROIN 2 Sheets-Sheet 1 Filed Feb. 11, 1964INVENTOR. WILLIAM B. WOSENITZ M\ g4 ATTORNEY Oct. 25, 1966 w. B.WOSENITZ GROIN 2 Sheets-Sheet 2 Filed Feb. 11, 1964 INVENTOR. WILLIAM B.WOSENITZ ATTOR-NEY United States Patent 3,289,569 GROIN Wiiliarn B.Wosenitz, Dania, Fla., assignor to Permagroin Company, Inc, BrowardCounty, Fla, a corporation of Florida Filed Feb. 11, 1964, Ser. No.344,056 2 Claims. (Cl. 61-4) This invention relates to beach erosionpreventing apparatus primarily to prevent the washing away of beachareas such as sandy beaches or in exceptional storm conditions, couldwash away gravel beaches.

It is well known that storms, and off-shore currents flowing past manybeaches often work to eventually destroy the beaches. This depletion ofa beach is caused by the sand being taken up therefrom and carried awaywith the current and subsequently deposited at some other point in thepath of the flow of water.

An object of the invention is to provide a groin or break-waterbasically having the characteristics of a permeable structure throughwhich the water will flow or be retarded in its movement and broken upto deposit sand that is normally carried in waves and to build up thebeach to the desired level and with the groins being shiftable outwardlyafter the beach has been built up to further collect the sand and toextend the beach outwardly from a mainland area.

The invention further contemplates a precast permeable groin that isideally suited for shallow sloping beaches, such as those particularlyin the Florida area. The groins are formed by molding or casting ahollow tunnel-like groin that has its side walls perforated and with theends of the groins being formed open and when connected in end to endrelation constitute the tunnel through which water and sand will flow.

Novel features of construction and operation of the device will be moreclearly apparent during the course of the following description,reference being had to the accompanying drawings wherein has beenillustrated a preferred form of the device and wherein like charactersof reference are employed to denote like parts throughout the severalfigures.

In the drawings:

FIGURE 1 is a plan view of a plurality of groins in end to end abuttingrelation and embodying the invention,

FIGURE 2 is a vertical longitudinal section taken sub-- stantially online 2-2 of FIGURE 1,

FIGURE 3 is a transverse vertical section taken substantially on line 33of FIGURE 2,

FIGURE 4 is a fragmentary end perspective view of one groin,

FIGURE 5 is a composite perspective view of elements embodied in thegroins,

FIGURE 6 is a slightly enlarged end elevation of the groin members shownin FIGURE 5 and in assembled relation with respect to a lower coveringslab, and

FIGURE 7 is a similar view showing the complete groin with both upperand lower covering slabs.

Referring specifically to the drawings and particularly to FIGURE 1,there has been provided a plurality of groins 5 arranged in end to endabutting relation and extending from the beach 6 and to a predeterimneddistance into the water, indicated at 7.

The groin is preferably formed by two substantially identical sections 8forming side walls 9. The side walls 9 are each provided withsubstantially identical U-shaped legs 10 all molded integral with thesides 9 and constituting spacers for the walls 9. The opening formed bythe legs 10 and a connecting rib 11 form at assembly, an open end foreach end of the groin, the opening being indicated in FIGURES 6 and 7,by the numeral 12. The openings 3,289,569 Patented Oct. 25, 1966 ice 12formed by the assembly of the members 8 provide an elongated tunnel andthe tunnel is continuous through adjacent groin members for permitting alongitudinal flow of water.

The side members 8, see particularly FIGURES 6 and 7, show the legs 10in abutting relation and each leg 10 may be recessed as indicated at 13to receive concrete key elements 14 which at assembly, prevent twistingor otherwise shifting of the members 8 under the impact of handling orwave conditions. The members 8 are provided with reinforcing steel thatprojects above the marginal edges of the side walls 9 and the legs 10,as indicated at 15 and whereby to rnoldably anchor upper and lower slabsof concrete, indicated at 16 and 17, see FIGURES 6 and 7. Each of theslabs 16 and 17 are provided with preferably square openings 18 that arein vertical alignment at assembly and adapted to receive preferablyconcrete pile forming members 19, that are driven through the openings18 to project below the slab 17 for embedment into the sand or bottom ofthe waterway. The piles 19 obviously will prevent either longitudinal ortransverse movement of the groins. While the piles 19 and the openings18 are shown as being square, they could obviously be round or any othershape.

Each of the side walls 9, are molded with a multiplicity of cylindricalapertures 20, such permitting the ready flow of water therethrough intothe tunnel formed by the groin and the apertures may be varied in sizeand number and while the openings may be varied upon the wall facingwindward and having a ratio of aperture to solid wall of approximatelyand the aperture ratio on the lee side may vary according to locationconditions but generally should be equal on both sides of the groin.

In the manufacture of the device, the members 8 are molded in a suitableform having members fixed thereto to form the openings 20. As will ofcourse be understood, the reinforcing steel placed within the members 20have portions thereof projecting above the upper and lower marginaledges to form the anchoring means for the slabs 16 and 17. After themembers 8 have been molded, they are removed from the mold and placedtogether, with the legs 10 in abutting relation and with the keys 14disposed within the apertures 13. The assembled members 8 are thendisposed upon a suitable flat surface at a predetermined elevation andthe top slab 16 then poured thereunder, being anchored to the extendingreinforcing 15. After the slab 16 has suitably hardened, the entire bodyis then turned over and similarly engaged with a slab 17. The anchoringof the slabs 16 and 17 ohviously will maintain the members 8 againstshifting and upon complete hardening or curing of the device, it is thensuitable to be installed as a groin. The groin may be moved intoposition at any desirable point or several of the groins may be arrangedin end to end relation to extend from the beach into the water as thesituation requires and anchored by the piling 19. When the groin is tobe extended into relatively deep water outwardly from the beach, thesides and ends may be covered and the openings 18 also covered and thedevice floated to the required site of installation. After the groinreaches the predetermined point for installing, the covering is removedand the groin allowed to sink to the bottom of the waterway at whichtime of course the additional piling 19 is driven into place and theopenings 12 provide a continuous tunnel through two or more groins.

Permeable box design with perforations will dissipate the kinetic waveenergy within the box chamber formed by the groin. Since the wave isforced into a jet as it passes through the first wall, it bouncesagainst the opposite wall and the upper slab end becomes aerated fromthe disturbance. As the wave flows through the aperescaping back throughthe holes is aerated and reduces the clapotis eifect of the next wave.

The aerated water and hole design reduces the scour action at thebottom. Since a specific gravity of aerated water is now less thannormal it helps prevent the suspended sand fr-om floating away. The samedesign permits thecoupling of one section to another. As accreationoccurs, sections may be extended with land based.

equipment. It has been estimated that the weight of the average 30 footsection is approximately 1213 tons, this plus the suction effect'ofapproximately 1500 pounds per square foot, the two pilings will befixedly held in its lateral position. Any hurricane or tidal wave ofsuch magnitude that would tend to shift or undermine any other design,would not effect this structure because it would merely settle to thenew bottom level. If this should ever occur, the design is made in sucha way that additional groins may be superposed upon the original groinsand longer piling driven therethrough. It is also possible that aftersand has built up and filled the tunnels of the units, they may beshifted further outwardly by breaking away the pilings and then toengage other pilings through the openings 18 at the new location.

It will be apparent from the foregoing that a permeable groin has beenprovided that is economically formed and assembled and that will bemosteffective for controlling wave movements and to most effectivelybuild up the sand on the eroded beach areas. The device can be formed insections as described or the body, of the groin described as sections 8can conceivably be molded as a unitary structure. The slabs 17 rest uponthe bottom and constitute a support for the groin while the slab 16overlies the groin for its full width and length and may con stitute apier walk-away, permitting persons to walk over the groin and, when thegroin extends sufiiciently far into the water, may constitute a verydesirable fishing pier. The device is strong, durable and most effectiveas a permeable groin and may beeasily and quickly assembled on theeroded beach areas at a minimum cost.

It is to be understood that the invention is not limited to the preciseconstruction shown, but that changes are contemplated as readily fallwithin the spirit of the invention as shall be determined by the scopeof the subjoined claims.

I claim:

1. A permeable groin of the character described comprising, an elongatedbox-like structure composed of a plurality of units placed inend-t-o-end relation and defining a tunnel through them, each unitconsisting of a pair of substantially identical wall-forming sections ofmolded concrete, the side walls of said sections having a multiplicityof openings through them, the groin being closed at the top by a slaband also closed at the bottom by a similar slab, said slabs beinganchored to the wall-forming sections, each of the. Wall-formingsections having U- shaped legs at its ends, the legs on one wall-formingsection being in abutting relation with the legs onthe opposite sectionto provide for spacing between the walls of the wall-forming sections,the slabs at the upper and lower ends of the-side walls being,apertured, the groin being positioned on a beach with the tunneltherethrough extending from the beach into the body of water on whichthe beach fronts, piling extending through the slabs and extendingthrough the groin units and into the beach and the bed of the body ofwater.

2. A groin of the character described for preventing beach erosion, thegroin being elongated and of hollow box-like construction, the groinbeing formed of-a pair of spaced-apart reinforced concrete side wallswith each side wall being provided with upper and lower leg extensionsdisposed at right angles to the side: walls and with said leg extensionshaving abutting engagement and constituting spacing means to locate theside walls apart, means for anchoring the legs together in theirabutting relation, an upperclosure slab of concrete co-extensive withthe groin, a lower reinforced concrete slab anchored to the reinforcingof the side walls and the legs, the legs at the opposite ends of thegroin defining square openings at such ends and defining the ends of atunnel extending through the groin, aligned openings formed in the topand bottom slabs for the passage of anchoring piles, each of the sidewalls being provided with amultiplicity of openings extending throughthem for the passage of water from waves that impinge against the sideof the groin, said openings causing the waves to dissipate their kineticenergy within the groin, the waves in their passage through the openingsin the side walls striking against the upper slab and causing the waterto deposit any sand that has collected in the waterway and flows throughthe tunnel in the groin; the groin being positioned on a beach with thetunnel therethrough extending from the beach into the body of water onwhich the beach fronts, piling extending through the apertures in theslabs and extending through the groin and into the beach and the bed ofthe body of water.

References Cited by the Examiner UNITED STATES PATENTS 954,283 4/1910Hawkes 6-l--4 1,277,829 9/1918 Baum 52-303 X 2,135,337 11/1938 Herbest61-4 2,474,786 6/ 1949 Humphrey 6l-4 2,514,119 7/1950 Boccia 61-42,645,114 7/1953 Amirikian 52-259 X 3,100,953 8/1963 Johnson. 52603 X-3,195,266 7/1965 Onanian 52585 X FOREIGN PATENTS 730,189 5/1932 France.

EARL I. WITMER, Primary Examiner.

1. A PERMEABLE GROIN OF THE CHARACTER DESCRIBED COMPRISING, AN ELONGATEDBOX-LIKE STRUCTURE COMPOSED OF A PLURALITY OF UNITS PLACED IN END-TO-ENDRELATION AND DEFINING A TUNNEL THROUGH THEM, EACH UNIT CONSISTING OF APAIR OF SUBSTANTIALLY IDENTICAL WALL-FORMING SECTIONS OF MOLDEDCONCRETE, THE SIDE WALLS OF SAID SECTIONS HAVING A MULTIPLICITY OFOPENINGS THROUGH THEM, THE GROIN BEING CLOSED AT THE TOP BY A SLAB ANDALSO CLOSED AT THE BOTTOM BY A SIMILAR SLAB, SAID SLABS BEING ANCHOREDTO THE WALL-FORMING SECTIONS, EACH OF THE WALL-FORMING SECTIONS HAVINGUSHAPED LEGS AT ITS ENDS, THE LEGS ON ONE WALL-FORMING SECTION BEING INABUTTING RELATION WITH THE LEGS ON THE OPPOSITE SECTION TO PROVIDE FORSPACING BETWEEN THE WALLS OF THE